[PATCH][Aarch64] v2: Arithmetic overflow subv patterns [Patch 3/4]

[Michael Collison <Michael dot Collison at arm dot com>]

This is a respin of a AArch64 patch that adds support for builtin arithmetic overflow operations. This update separates the patch into multiple pieces and addresses comments made by Richard Earnshaw here:

https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00249.html

Original patch and motivation for patch here:

https://gcc.gnu.org/ml/gcc-patches/2017-05/msg01512.html

This patch contains new patterns for subv<mode> overflow patterns.

Bootstrapped and tested on aarch64-linux-gnu. Okay for trunk?

2018-05-31  Michael Collison  <michael.collison@arm.com>
	    Richard Henderson <rth@redhat.com>

	* config/aarch64/aarch64.md (subv<GPI>4, usubv<GPI>4): New patterns.
	(subti): Handle op1 zero.
	(subvti4, usub4ti4): New.
	(*sub<GPI>3_compare1_imm): New.
	(sub<GPI>3_carryinCV): New.
	(*sub<GPI>3_carryinCV_z1_z2, *sub<GPI>3_carryinCV_z1): New.
	(*sub<GPI>3_carryinCV_z2, *sub<GPI>3_carryinCV): New.

Attachment: gnutools-6308-pt3.patch
Description: gnutools-6308-pt3.patch